Keeps the lens cap from falling off without an issue. I was actually worried that the strap would interfere with the zoom of the lens or would slip off, but the strap was tight enough that it didn't move around a lot or slide off. Definitely worth the money for the amount of protection it provides. The only advice I'd give to anyone who buys this is not to let it dangle when you're taking pictures in the wind. I used it on my Nikon while on a cruise, and with taking pictures on the deck, the wind would catch it and constantly flop the cap around. All I had to do was pin the strap with my finger, though, and it was fine.

Rating: 5 of 5 Not sure this would do the job but ordered to see anyway. Very glad to discover that it is excellent and because there are three I will be able to use one on each of my other lenses, too. Adhesive is stronger than I expected and the elastic strap fits the lens perfectly. Would order again if necessary and recommend it to others who do not want to lose their lens caps.

Very convenient when you have multiple lenses. Easy to mount securely on lens and cap, keeping the lens cap with the lens.

Elastic band fits around lens so the lens cap stays with the right lens. Band has plenty of stretch and should fit lenses from about 6" in circumference (a bit under 2") to just under 12" in circumference (about 3-7/8" in diameter.) The cord extends about 5" from the band so use on very large telephoto lenses could be a problem.

I used these on my lens covers for my Canon T5i. They fell off after a few months when they were in the warm weather in AL. The adhesive just seemed to melt and the sticky pad separated from the tab. Not worth it -- get something better!

It is no secret that these work; I don't know why cameras don't come stock with these nowadays. But since these are so cheap and come in threes, it isn't that big of a deal. I'm hoping Amazon adds more stuff like these to their "add-on" items soon.

These specific keepers are very sticky, and I like that the adhesive tape is more like butyl rubber when you remove the backing. Unlike most two-sided tapes, this one is soft and almost viscous. Once you get that sucker on, it isn't coming off without a good amount of force.

The elastic tethers can be rolled and moved around or stretched and pinned up out of the way, and the elastic straps that go around the lens are made well and are shoelace-flat, so they don't get in the way of your grip.

I'd never used these before on my own setups (I habitually put the cap in my left pocket), but I bought these for my stepmother who uses a Tamron lens, and those caps are so springy that they jump off at the slightest jounce. Now that I have one, I'll never go without it.

All in all, a no-brainer kind of purchase.